The Tropical Prediction Center  (TPC)

The National Hurricane Center, a branch of TPC, prepares and distributes hurricane watches and warnings for the general public, and also prepares and distributes marine and military advisories for other users during the active season (beginning in May for the eastern Pacific and June for the Atlantic, and ending in late November).

How Storms are Tracked

Tools used to track tropical storms while they are far from shore include orbiting satellites and specialized aircraft that fly into the core of a hurricane to measure wind, pressure, temperature and humidity.

Once a tropical storm approaches land, land-based radar can begin to monitor it. The TPC, through the National Weather Service (NWS), then issues public advisories and strike probabilities. Traditionally these advisories, which contain forecasts of the cyclone's position, intensities and wind field, are issued as much as 72 hours in advance. However, with advancements in technology and improved modeling techniques, the NWS now offers five-day forecasts.

Tracking Storms in New York City

In New York City, OEM — working in close collaboration with the NWS, the NHC and state and federal officials — monitors any hurricanes or tropical storms that develop in the Atlantic Basin.

To effectively track coastal storms, OEM relies on several information sources, which include:

• New York State Police Information Network (NYSPIN)
• NOAA Weather Radio
• The Weather Channel
• New York State Emergency Management Office (SEMO) State Emergency Coordination Center via National Warning System
• SEMO Regional Conference Calls
• Consultation with the Federal Emergency Management Agency's (FEMA) Hurricane Liason Team (in PDF)
• Private meteorological services via fax and pager

OEM monitors tropical cyclones (hurricanes), extratropical cyclones (nor'easters) and coastal flooding events. Once a tropical depression is identified, OEM uses a software tool called HURREVAC that helps determine the probability and timing of a potential hurricane strike. Throughout the storm, OEM disseminates storm-related information to relevant agencies via radio, fax and e-mail.